The director of the American CIA, George Tenet, is due in Jerusalem on Monday to resume efforts to end the Middle East conflict.

A BBC correspondent in Jerusalem says Mr Tenet hopes to bring about a ceasefire this time through the reorganisation of the fragmented Palestinian security.

Nablus has been brought to a virtual standstill

Mr Tenet wants to see a more unified structure with a clear chain of command in control, but our correspondent says he must convince both the Israeli and Palestinian authorities that the security reforms represent their best interests.

Mr Tenet's visit comes as the Israeli army continues its operations in the West Bank. About 400 Palestinians were rounded up for questioning in the Ain Bet-Alma'a refugee camp next to the city of Nablus on Monday.

Security shake-up

In 2001, Mr Tenet brokered a deal under which both the Palestinians and Israelis agreed to a ceasefire ahead of a resumption of comprehensive peace talks.

The plan failed - scuppered by Palestinian suicide attacks on Israeli civilians and retaliatory Israeli military operations in the West Bank and Gaza Strip.

But the BBC's Jeremy Cooke in Jerusalem says the Americans clearly still see suspending hostilities on the ground as an essential first step towards any political progress.

The Israelis are carrying out house to house searches

Mr Tenet's big idea this time is the reorganisation of the fragmented and at times chaotic Palestinian security forces through the establishment of a more unified structure with a clear chain of command and control.

Our correspondent adds that Mr Tenet will try to convince Israel's Prime Minister Ariel Sharon that such a move would be a significant step forward.

The Americans are also trying to arrange an early meeting with Palestinian leader Yasser Arafat to convince him that now is the time for a major shake-up of his security structure.

Tensions high

Meanwhile Israel remains on the maximum level of security alert amid warnings that there will be more suicide attacks.

On Monday Israeli tanks surrounded Ain Bet-Alma'a refugee camp near Nablus. Troops using loudspeakers called on all males between the ages of 15 and 50 to come out of their homes for identification checks.

About 400 Palestinians were taken away in buses and trucks to a nearby army base for questioning.

Since Friday, the Israeli Army has virtually closed down Nablus, enforcing a round the clock curfew while the army has been searching for militants.

On Sunday the troops blew up two houses where the
army said it found workshops where suicide bombs were being made.